Cable assembler

ABSTRACT

A cable assembler which makes it possible to carry out in a short tact time the assembling of cable terminal which needs a plurality of jigs and tools. A robot delivers a bobbin of cable to various stations in a working area. Processing in accordance with the invention reduces tact time.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is related to and claims priority from JapanesePatent Application No. 2000-168444, filed on Jun. 6, 2000.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a cable assembler, and moreparticularly, to a cable assembler suitable for the terminal finishingof optical cable.

[0003] The conventional automatic assembler by a robot usually operatesin such a way that the work is fixed on a previously arranged assemblingline and the robot does assembling according to the previous establishedprocedure. An example of such conventional automatic assemblers isdisclosed in Japanese Patent Laid-open No. 320363/1994. It consists ofseveral robots arranged back to back on one station of a previouslyinstalled line. The robots move and rotate to do complicated assemblingoperations.

[0004] Unfortunately, the assembling system disclosed in Japanese PatentLaid-open No. 320363/1994 has the disadvantage of requiring many robotsand many stations on the line for the process, such as the terminalfinishing of optical cable, which needs a plurality of complex tools andjigs. This leads to a long period and a large expense for development.The disadvantage of this system is that the tact time becomes longerbecause the number of steps to be carried out in one station increases.

[0005] There is a need to provide a cable assembler which is capable ofthe terminal finishing of cable in a short tact time even though theterminal finishing requires a plurality of jigs and tools.

SUMMARY OF THE INVENTION

[0006] The first aspect of the present invention resides in a cableassembler of the type having a robot which holds and moves the work by amechanical hand attached to the forward end thereof and a plurality ofprocessing means arranged within the working area of the robot, saidrobot moves the work sequentially from one processing means to anotherfor the execution of individual processing, wherein said robot transfersworks such that one work undergoes one processing while the other workundergoes another processing which takes a longer time among a pluralityof processing steps.

[0007] This constitution reduces tact time because the work istransferred to the step which takes a long processing time while theother work is being processed by other processing means.

[0008] The second aspect of the present invention resides in the cableassembler as defined the first aspect above, wherein the processingmeans to receive said work consists of a plurality of processing meanshaving identical functions and said robot transfers the work to theprocessing means which is idle among the plurality of processing means.

[0009] This constitution reduces tact time further owing to paralleloperation by a plurality of processing means having identical functions.

[0010] The third aspect of the present invention resides in the cableassembler as defined in the first aspect above, wherein said mechanicalhand is provided with a chuck which has the mechanism to hold the workand change the direction of the held work.

[0011] This constitution simplifies the construction of the processingmeans.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a plan view showing the layout of the entire structureof the cable assembler according to an illustrative embodiment of thepresent invention;

[0013]FIG. 2 is a fragmentary sectional view showing the structure ofthe terminal of the optical cable which has undergone terminalprocessing by the cable processing apparatus according to anillustrative embodiment of the present invention;

[0014]FIG. 3 is a perspective view showing the structure of a mechanicalhand used for the pre-finishing station of the cable assembler shown inFIG. 1, according to an illustrative embodiment of the presentinvention;

[0015] FIGS. 4(A)-4(G) show the steps which are carried out by thepre-finishing station of the cable assembler shown in FIG. 1, accordingto an illustrative embodiment of the present invention;

[0016]FIG. 5(A) is a perspective view of the mechanical hand used forthe post-finishing station of the cable assembler shown in FIG. 1,according to an illustrative embodiment of the present invention;

[0017]FIG. 5(B) is an expanded view of the circled portion of themechanical hand shown in FIG. 5(A);

[0018] FIGS. 6(A)-6(E) are perspective views showing the actions of theconnector inserter used for the post-finishing station of the cableassembler shown in FIG. 1, according to an illustrative embodiment ofthe present invention; and

[0019]FIG. 7 is a diagram showing the processing which occurs in thepost-finishing station of the cable assembler shown in FIG. 1, accordingto an illustrative embodiment of the present invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0020] The invention will be described with reference to FIGS. 1 to 7which illustrate the construction and mechanism of a cable assemblermerely as an example of an embodiment of the present invention. Inparticular, the following explanation is made in reference to a cableassembler that handles optical fiber of twin-core type for its terminalfinishing.

[0021] First, the entire construction of the cable assembler accordingto the present invention is explained below with reference to FIG. 1.FIG. 1 is a plan view showing the layout of the cable assembleraccording to the present invention.

[0022] The cable assembler according to the present invention comprisesa pre-finishing station 10 and a post-finishing station 30. Thepre-finishing station 10 includes a horizontal articulated robot 11having a mechanical hand 20 at its forward end. Within the working areaof the horizontal articulated robot 11 are arranged a plurality ofworkstations including an outer coat stripper 13, a sleeve inserter 14,and a crimper 15.

[0023] A detailed description of the components 13, 14, and 15 will begiven later with reference to FIG. 3. An outline is given here.

[0024] A loader-unloader 12 receives a cable bobbin 60 (as a work) whichis manually placed thereon. The bobbin 60 has an optical fiber cable 50wound thereon. From the bobbin 60, protrude both ends of the cable(designated by 50A and 50B) which are to undergo terminal finishing.

[0025] The horizontal articulated robot 11 has joints J1 and J2. Therobot 11 rotates about a center J0. The portion of the robot between thecenter 10 and the joint J1 rotates in the direction of arrow A1. Theportion of the robot between the joint J1 and the joint J2 rotates inthe direction of arrow A2. To the forward end of the joint J2 isattached a mechanical hand 20, which rotates in the direction of arrowA3. In addition, the center of the robot 11 is movable in the verticaldirection (i.e., in a direction above and below the plane of the paper).Consequently, the mechanical hand 20 attached to the forward end of thehorizontal articulated robot 11 is movable in three-dimensions.

[0026] The outer coat stripper 13 cuts and removes the outer coat of theeach end 50A, 50B of the optical fiber 50 and then cuts the Kevlar. Thesleeve inserter 14 inserts the end of the optical fiber 50 into thestrain relief. The crimper 15 slips a crimping ring on the end of theoptical fiber 50 and then crimps the crimping ring.

[0027] A detailed description of the mechanical hand 20 will be givenlater with reference to FIG. 3. The mechanical hand 20 loads the work 60from the loader-unloader 12, and moves it to the outer coat stripper 13which cuts the outer coat. Then, the mechanical hand 20 moves the work60 to the sleeve inserter 14 which inserts a strain relief. Then, themechanical hand 20 moves the work 60 to the crimper 15 which crimps thecrimping ring. When the crimping step is completed, the mechanical hand20 unloads the work 60 back to the loader-unloader 12.

[0028] The post-finishing station 30 constitutes a cable work areahaving a horizontal articulated robot 31 which has a mechanical hand 40at its forward end. Within a first area in the working area of thehorizontal articulated robot 31 are arranged a plurality of workstationsincluding a loader station 32, an inner coat stripper 33, and aconnector part inserter 34. A second area in the working area includesan adhesive setter 35. A third area in the working area includes anotherplurality of workstations, including a grinder 36, a polisher 37, and anunloader 38. The adhesive setter 35 comprises a plurality of identicalcuring ovens, first through third ovens 35A, 35B, and 35C.

[0029] A detailed description of what the components 33 to 37 do will begiven later with reference to FIG. 4. An outline is given here.

[0030] The loader station 32 receives from the loader-unloader 12 acable bobbin 60 that has undergone the pre-finishing step discussedabove. The cable bobbin is manually transferred from the loader-unloaderto the loader station 32.

[0031] The horizontal articulated robot 31 has joints J1 and J2. Therobot 31 rotates about a center J0. The part between the center J0 andthe joint J1 rotates in the direction of arrow B1. The part between thejoint J1 and the joint J2 rotates in the direction of arrow B2. To theforward end of the joint J2 is attached a mechanical hand 40, whichrotates in the direction of arrow B3. The center J0 of the robot 31 ismovable in the vertical direction (i.e., in a direction above and belowthe plane of the paper). In other words, the mechanical hand 40 attachedto the forward end of the horizontal articulated robot 31 is movable inthree-dimensions.

[0032] The robot 31 is controlled by a controller 31CONT. The controller31CONT communicates via communication lines 31COMM with the inner coatstripper 33, the connector part inserter 34, the adhesive setter 35, thegrinder 36, and the polisher 37 through communications circuits. Thecontroller receives signal from the devices indicating the completion ofoperation from each device.

[0033] The inner coat stripper 33 strips the inner coat of the opticalcable 50 and removes the primary coat. The connector part inserter 34inserts connector parts (to which an adhesive has been applied) into theend of the optical cable 50. The adhesive setter 35 heats and cures theadhesive. The grinder 36 removes the adhesive and the core protrudingfrom the end of the connector part. The polisher 37 polishes the endsurface of the connector part.

[0034] After terminal finishing according to the present invention, theend of the optical cable has a structure as shown in FIG. 2.

[0035]FIG. 2 is a sectional view showing the structure of the end of theoptical cable which has undergone terminal finishing by the cableassembler according to the present invention. FIG. 2 shows the opticalfiber, with its inner coat stripped off by the inner coat stripper 33.

[0036] The optical cable 50 comprises two cores 51. Each core is coveredwith a primary coat 52A. Disposed over the primary coat is an inner coat52. The two cores are covered with an outer coat 54. Between the innercoat 52 and the outer coat 54 is interposed the Kevlar 53. The core 51is 0.2 mm in diameter, for example. The outer coat 52 is made of Teflonand 2 mm in diameter, for example. The Kevlar 53 is a long plasticstring comprised of thousands of fibers interposed between the outercoat 54 and the inner coat 52. The Kevlar 53 protects the core 51. Theouter coat 54 is made of polyvinyl chloride and is 10 mm in outsidediameter, for example.

[0037] With the end of the inner coat 52 cut and removed, the core 51 isexposed. At the end of the optical cable 50, a sleeve Sv is insertedbetween the Kevlar 53 and the inner coat 52. The sleeve Sv is made ofpolyvinyl chloride, for example. The end of the outer coat 54 is coveredwith a strain relief Sr. The strain relief Sr is made of polyvinylchloride, for example. It relives the stress which the optical fiber 50receives when it is bent. To the end of the strain relief Sr is fittedan inner crimp ring Ir, which is made of brass, for example. The innercrimp ring Ir has a knurled outer surface. The crimping ring Pr isslipped on the Kevlar 53 which has been folded back. The inner crimpring Ir (between the strain relief Sr and the crimping ring Pr) is fixedto the Kevlar 53 by application of pressure from outside. The crimpingring Pr is made of copper, for example.

[0038] What occurs in the pre-finishing station 10 of the cableassembler of the present invention is explained with reference to FIGS.1 to 4.

[0039] First, an explanation is made below with reference to FIG. 3 ofthe mechanical hand 20 used in the pre-finishing station 10 of the cableassembler of the present invention.

[0040]FIG. 3 is a perspective view showing the construction of themechanical hand 20 used in the pre-finishing station 10 of the cableassembler as one embodiment of the present invention.

[0041] The mechanical hand 20 has a cable bobbin chuck 22 comprisingarms 22A and 22B. The arms 22A and 22B swing (to open and close)respectively in the direction of arrows C1 and C2 around the support onthe base 21 of the mechanical hand 20. With the cable bobbin chuck 22opened, the bobbin 60 (as the work) is set. As the cable bobbin chuck 22is closed, the bobbin 60 is clamped by the chuck and held.

[0042] The base 21 has forward chucks 23A and 23B and forward chucks 24Aand 24B. The forward chuck 23A is movable in the direction of arrow C3,and the forward chuck 23B is movable in the direction of arrow C4. Theforward chucks 23A and 23B are moved in such a direction that theirseparation distance increases. While the forward chucks 23A and 23B areapart, an end of the optical fiber 50A is arranged. Then, the forwardchucks 23A and 23B are moved in such a direction that their separationdistance decreases. In this way the end of the optical cable 50A isheld.

[0043] Similarly, the forward chuck 24A is movable in the direction ofarrow C5, and the forward chuck 24B is movable in the direction of arrowC6. The forward chucks 24A and 24B are moved in such a direction thattheir separation distance increases. While the forward chucks 24A and24B are apart, another end of the optical fiber 50B is arranged. Then,the forward chucks 24A and 24B are moved in such a direction that theirseparation distance decreases. In this way the end of the optical cable50B is held.

[0044] What is done by the pre-finishing step is explained withreference to FIGS. 4(A)-4(G) and FIG. 1.

[0045] FIGS. 4(A)-4(G) show the steps carried out in the pre-finishingstation 10 of the cable assembler as one embodiment of the presentinvention.

[0046] First, the horizontal articulated robot 11 moves to the positionof the loader-unloader 12. The mechanical hand 20 attached to theforward end of the horizontal articulated robot 11 grips the bobbin 60that had been previously manually loaded on the loader-unloader 12.

[0047] The horizontal articulated robot 11 inserts an end 50A of theoptical cable 50 (which is held by the mechanical hand 20) into theouter coat stripper 13. As shown in FIG. 4(A), the outer coat stripper13 cuts and removes the outer coat 54 at the end of the optical fiber50, and it also cuts the Kevlar 53.

[0048] When the removal of the outer coat 54 and the cutting of theKevlar 53 are completed, the horizontal articulated robot 11 moves theends of the optical cable 50 (held in place by the mechanical hand 20)to the sleeve inserter 14. As shown in FIG. 4(A), the sleeve inserter 14slips the strain relief Sr on the end of the optical fiber 50. Itfurther slips the inner crimp ring Ir on the end of the strain reliefSr. As shown in FIG. 4(B), the sleeve inserter 14 further slips thesleeve Sv on the part between the Kevlar 53 and the inner coat 52. Afterthe sleeve Sv has been slipped on, the sleeve inserter 14 moves thestrain relief Sr toward the end of the optical cable such that theKevlar 53 and the outer coat 54 are held between the sleeve Sv and thestrain relief Sr.

[0049] After the sleeve Sv has been slipped on, the horizontalarticulated robot 11 moves the ends of the optical cable 50 to thecrimper 15. The crimper 15 folds back the end of the Kevlar 53, as shownin FIG. 4(C). Further, the crimper 15 slips the crimping ring Pr on theend of the optical fiber 50, as shown in FIG. 4(D), and then appliespressure to the periphery of the crimping ring Pr so as to deform andcrimp the crimping ring Pr.

[0050] When the slipping on of the crimping ring Pr is completed, thehorizontal articulated robot 11 transfers the bobbin 60 to the positionof the loader-unloader 12 and then unloads the bobbin 60.

[0051] With the bobbin 60 placed on the loader-unloader 12, the washerspring Ws is slipped on the periphery of the inner coat 52, as shown inFIG. 4(E). This step is carried out manually rather than mechanicallybecause manual operation is more efficient. To complete the previouscrimping step, the washer spring is slipped on within the tact time, andthe work (bobbin 60) is set on the loader station 32. In one embodimentof the invention, the work is manually transferred from theloader-unloader 12 to the loader station 32.

[0052] What is done by the post-finishing station 30 of the cableassembler will be described with reference to FIGS. 5, 6, 1, and 4.

[0053] First, an explanation is made below with reference to FIGS. 5(A)and 5(B) of the construction of the mechanical hand 40 used in thepost-finishing station 30 of the cable assembler in one embodiment ofthe present invention.

[0054]FIG. 5(A) is a perspective view showing the mechanical hand 40used in the post-finishing station 30 of the cable assembler in oneembodiment of the present invention. FIG. 5(B) is an enlarged view ofthe circled portion of the mechanical hand shown in FIG. 5(A).

[0055] A cable bobbin chuck 42 of the mechanical hand 40 opens andcloses in the directions of arrows D1 and D2, moving around the supportof the mechanical hand 40 on the base 41. With the cable chuck bobbin 42opened, the bobbin 60 (as the work) is set, and the cable chuck bobbin42 is closed so as to hold the bobbin 60.

[0056] On the base 41 are mounted the outer coat chucks 43A and 43B andthe outer coat chucks 44A and 44B. The outer coat chuck 43A is movablein the direction of arrow D3, and the outer coat chuck 43B is movable inthe direction of arrow D4. The outer coat chucks 43A and 43B move insuch a direction that their separation distance increases. While theyare apart, one end 50A of the optical cable 50 is arranged. Then, theouter coat chucks 43A and 43B move in such a direction that theirseparation distance decreases. In this way the chuck grips onto theouter coat 54 of the end of the optical cable 50A. Also, the outer coatchuck 44A is movable in the direction of arrow D5, and the outer coatchuck 44B is movable in the direction of arrow D6. The outer coat chucks44A and 44B move in such a direction that their separation distanceincreases. While they are apart, the other end of the optical cable 50is arranged. Then, the outer coat chucks 44A and 44B move in such adirection that their separation distance decreases. In this way theouter coat 54 of the other end 50B of the optical cable 50 is held.

[0057] To the forward end of the outer coat chuck 43A is attached theend chuck 45A. The end chuck 45A holds the inner coat 52 of one of thetwo cores 51 at one end 50A of the twin-core optical fiber 50. To theforward end of the outer coat chuck 43B is attached the end chuck 45B.The end chuck 45B holds the inner coat 52 of the other of the two cores51 at one end 50A of the twin-core optical fiber 50.

[0058] To the forward end of the outer coat chuck 44A is attached theend chuck 46A. The end chuck 46A holds the inner coat 52 of one of thetwo cores 51 at one end 50B of the twin-core optical fiber 50. To theforward end of the outer coat chuck 44B is attached the end chuck 46B.The end chuck 46B holds the inner coat 52 of the other of the two cores51 at one end 50B of the twin-core optical fiber 50.

[0059] Referring to FIGS. 5(A) and 5(B), the end chucks 45A, 45B, 46A,and 46B are movable in the direction of arrow E. The end chucks 45A,45B, 46A, and 46B are rotatable upward through 90° (from a neutralposition A) in the direction of arrow E1 to and upward position A+.Hence the end chucks can direct the core 51 upward (vertically). The endchucks can also fix the core 51 at any angle between horizontal (neutralposition A) and the upward vertical position A+.

[0060] Moreover, the end chucks 45A, 45B, 46A, and 46B are rotatabledownward through 90° (from the neutral position A) in the direction ofarrow E2, as shown in FIG. 5(B) to a downward vertical position A−.Hence the end chucks can direct the core 51 downward (vertically). Theend chucks can also fix the core 51 at any angle between neutralposition A and vertical downward position A−.

[0061] In other words, the end chucks 45A, 45B, 46A, and 46B of themechanical hand 40 can move independently in the directions of E1 and E2and change the direction of the cable end and hold it at a desiredangle. The mechanical hand 40 changes the direction of the cable end inalignment with the setting direction of the stations. Therefore, itsimplifies the construction of the single-function automatic machine.

[0062] The pre-finishing step will be explained with reference to FIGS.4(A)-4(G) and 1.

[0063] First, the horizontal articulated robot 31 moves to the positionof the loader-unloader 32. To the forward end of the horizontalarticulated robot 31 is attached the mechanical hand 40. The mechanicalhand 40 grips for loading the bobbin 60 placed on the loader-unloader32. As explained with reference to FIGS. 5(A) and 5(B), the outer coatchucks 43A and 43B and the outer coat chucks 44A and 44B of themechanical hand 40 hold both ends of the optical fiber 50, and the endchucks 45A, 45B, 46A, and 46B hold the inner coat 52 corresponding tothe respective cores.

[0064] Then the horizontal articulated robot 31 inserts the end of theoptical cable 50 (which is held by the mechanical hand 40) into theinner coat stripper 33. At this time, the end chucks 45A, 45B, 46A, and46B insert it into the inner coat stripper 33, with the optical cableheld such that the inner coat 52 is horizontal (neutral position A), asshown in FIG. 5(B).

[0065] The inner coat stripper 33 strips the end part of the inner coatof the optical cable 50. FIG. 4(D) shows the cable before stripping, andFIG. 4(E) shows the cable after stripping. Then, the inner coat stripper33 removes the inner coat covering the periphery of the core 51. Theinner coat may be silicone rubber, for example.

[0066] Next, the horizontal articulated robot 31 moves the end of theoptical cable 50 (which is held by the mechanical hand) to the connectorpart inserter 34. At this time, the end chucks 45A, 45B, 46A, and 46Brotate through 90° in the direction of arrow E1, as shown in FIG. 5(B),and move to the connector part inserter 34 while holding the opticalcable such that the inner coat 52 points upward. The connector partinserter 34 slips the connector part Cp (which is filled with anadhesive) on the end of the optical cable 50, as shown in FIG. 4(F).

[0067] What is done by the connector part inserter 34 (which is used inthe post-finishing station 30 of the cable assembler) is explained belowwith reference to FIGS. 6(A)-6(E).

[0068] FIGS. 6(A)-6(E) are perspective views illustrating the operationof the connector part inserter 34 in the post-finishing station 30 ofthe cable assembler.

[0069] In this embodiment, the connector part inserter 34 communicateswith the controller 31CONT of the robot 31 through the communicationport, as explained above with reference to FIG. 1. Owing tocommunications between them, the controller 31CONT of the robot 31 helpsthe operation of the connector part inserter 34.

[0070] The controller 31CONT of the robot 31 starts communications withthe connector part inserter 34 to make sure that the connector partinserter 34 is ready to work. Then, the controller 31CONT of the robot31 issues an operation start command to the connector part inserter 34.At the same time, the mechanical hand 41 moves in the direction of arrowF1 while holding the cores of the optical cables 50A and 50B upward, andtransfers them to the stationary core guide 34A of the connector partinserter 34, as shown in FIG. 6(A). When the end chucks 45 and 46 havemoved over a prescribed distance, the connector part inserter 34 isinformed of the arrival of the cores of the optical cables 50A and 50B.

[0071] Then, upon receipt of the operation start command, the connectorpart chuck 34B of the connector part inserter 34 holds the connectorpart Cp and fills it with an adhesive and feeds the connector part Cp tothe insertion starting position, as shown in FIG. 6(A). The connectorpart Cp is made of ceramics, for example. If information of the arrivalto the connector part insertion position has been received from thecontroller 31CONT of the robot 31, the movable core guide 34C and theconnector part chuck 34B of the connector part inserter 34 move down inthe direction of arrow F2, so that the connector part Cp (which is heldby the connector part chuck 34B) is slipped on the core of the end ofthe optical cable, while the core of the optical cable is guided in thecenter direction of the connector part Cp by the movable core guide 34C.After movement over a prescribed distance, the connector part inserter34 informs the controller 31CONT of the robot 31 of the completion ofthe temporary slipping on of the connector part Cp. Incidentally, at thetime of the completion of the temporary slipping on, the connector partCp is not yet slipped on to the final position.

[0072] Upon receipt of information of the completion of operation fromthe connector part inserter 34, the controller 31CONT of the robot 31causes the mechanical hand 41 to move upward in the direction of arrowF3, as shown in FIG. 6(B), so as to move the connector part Cp to itsfinal position. The final position is a position at which the forwardend of the core protrudes from the central hole of the connector partCp. The movement in the direction of arrow F3 is accomplished by slidingthe axis J0 of the robot 31 in the vertical direction with respect topaper. The completion of the complimentary action of the connectorinserter 34 is informed to the connector part inserter 34 by thecontroller 31CONT.

[0073] Upon receipt of information of the completion of thecomplimentary action from the controller 31CONT of the robot 31, theconnector part inserter 34 moves the dividable movable core guide 34Cand the connector part chuck 34B in the respective directions of arrowsF4 and F5, as shown in FIG. 6(C), so as to release the connector part Cp(as the work) and informs the controller 31CONT of the robot 31 of thecompletion of operation.

[0074] Then, in response to the signal indicating the completion ofoperation by the connector part inserter 34, the robot 31 moves the endchucks 45 and 46 in the direction of arrow F6, as shown in FIG. 6(D),and starts the next step. At the same time the connector part inserter34 moves the movable core guide 34C and the connector chuck 34B in thedirection of arrow F7, thereby helps the discharge by the robot, andthen returns to the neutral position to become ready for the nextoperation.

[0075] When the slipping on of the connector part Cp by the connectorpart inserter 34 is completed, the connector part Cp is fitted to theforward end of the inner coat 52 and the core 51 protrudes from thecenter hole of the connector part Cp, as shown in FIG. 4(f).

[0076] Then, the horizontal articulated robot 31 moves the end of theoptical cable 50 (which is held by the mechanical hand 40) to theadhesive setter 35. The adhesive setter 35 comprises three identicalcuring ovens 35A, 35B, and 35C. The controller 31CONT of the robot 31transfers the end of the optical cable 50 to any of the curing ovenswhich is not in use. At this time, the end chucks 45A, 45B, 46A, and 46Brotate through 90° in the direction of arrow E1, as shown in FIG. 5(B),and move the optical cable to the curing oven while holding it such thatthe inner coat 52 points upward.

[0077] The adhesive setter 35 needs heat-curing for more than 20 minutesin the post-finishing step. Therefore, the mechanical hand 40 of therobot 31 transfers the optical cable (as the work) to one of the curingovens 35A, 35B, and 35C, thereby releasing the robot 31 and allowing theoptical cable (as the other work) to be processed. The adhesive to bepacked into the connector part Cp is of two-pack type. It cures uponheating at 130° C. for 20 minutes. For the step that requires a longtime for processing, the robot transfers the optical cable (as the work)so as to release itself and save the total tact time. The paralleloperation of the three curing ovens reduces the tact time. More abouttact time will be explained later with reference to FIG. 7.

[0078] When the heating step is completed, the mechanical hand 40 of thehorizontal articulated robot 31 receives the optical cable from thecuring oven 35 of the adhesive setter 35 and moves the end of theoptical cable 50 held thereby to the grinder 36. At this time, the endchucks 45A, 45B, 46A, and 46B rotate through 90° in the direction ofarrow E2 and move to the connector part inserter 34, while holding theoptical cable such that the end of the core 51 points downward, as shownin FIG. 5(B). The grinder 36 cuts the core 51 protruding (5-10 mm) fromthe end of the connector part Cp and roughly grinds the end of theconnector part Cp, as shown in FIG. 4(f), so as to remove the adhesivewhich has cured after leakage from the end of the connector part Cp, asshown in FIG. 4(g).

[0079] Then, the horizontal articulated robot 31 moves the end of theoptical cable 50 (which is held by the mechanical hand 40) to thepolisher 37. At this time, the end chucks 45A, 45B, 46A, and 46B rotatethrough 90° in the direction of arrow E2 and move to the connector partinserter 34, while holding the optical cable such that the end of thecore 51 points downward, as shown in FIG. 5(B). The polisher 37 polishesthe end surface of the connector part Cp. The polisher 37 takes 8minutes for polishing. Therefore, the mechanical hand 40 transfers theoptical cable to the polisher 37 temporarily so as to make the robot 31free. The polisher 37 employs two kinds of polishing paper (rough andfine) so as to polish the end of the connector part Cp, particularly theend of the core 51.

[0080] When the polishing by the polisher 37 is completed, themechanical hand 40 of the horizontal articulated robot 31 receives theoptical cable from the polisher 37 and moves to the unloader 38 tounload the bobbin 60 (as the work).

[0081] In what follows, the processing of the post-finishing step of thecable assembler in one embodiment of the present invention is explainedwith reference to FIG. 7.

[0082]FIG. 7 is a diagram showing what is done by the post-finishingstation 30 of the cable assembler in one embodiment of the presentinvention.

[0083] In FIG. 7, the abscissa represents time, each division denoting 2minutes, and the ordinate represents devices. In other words, (31) atthe bottom of the ordinate represents the operating state of the robot31. (32) on the ordinate represents the loader 32. (33) on the ordinaterepresents the operating state of the inner coat stripper 33. (34) onthe ordinate represents the operating state of the connector partinserter 34. (35) on the ordinate represents the operating state of theadhesive setter 35. The adhesive setter 35 comprises three curing ovens35A, 35B, and 35C. (36) on the ordinate represents the operating stateof the grinder 36. (37) on the ordinate represents the operating stateof the polisher 37. (38) on the ordinate represents the unloader 38.Circled alphabets A to H respectively denote the bobbins 60A to 60Hwhich are different works.

[0084] First, the horizontal articulated robot 31 loads the bobbin 60Afrom the loader 32, and then moves it to the inner coat stripper 33 andexecutes the stripping of the inner coat. The inner coat stripper 33takes 2 minutes for its processing. Incidentally, this processing timeincludes time required for movement from the previous step (the loader32 in this case) to the inner coat stripper 33. In each step mentionedlater, the processing time includes time required for movement from theprevious step.

[0085] When the inner coat stripping for the bobbin 60A is completed,the horizontal articulated robot 31 moves the bobbin 60A from the innercoat stripper 33 to the connector part inserter 34, so that theconnector part is slipped on. The connector part inserter 34 takes 4minutes for its processing.

[0086] After the bobbin 60A has undergone the slipping on of theconnector part, the horizontal articulated robot 31 moves the bobbin 60Afrom the connector part inserter 34 to the adhesive setter 35. In thisstep, the horizontal articulated robot 31 moves the bobbin 60A to thecuring oven 35A and transfers the bobbin 60A to the curing oven 35A, soas to make it possible to handle the other work. The curing oven 35Atakes 20 minutes for its processing. In other words, up to this stage,the horizontal articulated robot 31 handles the bobbin 60A, as indicatedby (31) at the bottom of the ordinate in FIG. 7.

[0087] Then, the horizontal articulated robot 31 loads the bobbin 60Bfrom the loader 32 and moves it to the inner coat stripper 33 for thestripping of the inner coat. After the bobbin 60B has undergone innercoat stripping, the horizontal articulated robot 31 moves the bobbin 60Bfrom the inner coat stripper 33 to the connector part inserter 34 sothat the connector part is slipped on. After the bobbin 60B hasundergone the slipping on of the connector part, the horizontalarticulated robot 31 moves the bobbin 60B from the connector partinserter 34 to the curing oven 35B of the adhesive setter 35 andtransfers the bobbin 60B to the curing oven 35B. In other words, up tothis stage, the horizontal articulated robot 31 handles the bobbin 60B,as indicated by (31) at the bottom of the ordinate in FIG. 7.

[0088] Then, the horizontal articulated robot 31 loads the bobbin 60Cfrom the loader 32 and moves it to the inner coat stripper 33 for thestripping of the inner coat. After the bobbin 60C has undergone innercoat stripping, the horizontal articulated robot 31 moves the bobbin 60Cfrom the inner coat stripper 33 to the connector part inserter 34 sothat the connector part is slipped on. After the bobbin 60C hasundergone the slipping on of the connector part, the horizontalarticulated robot 31 moves the bobbin 60C from the connector partinserter 34 to the curing oven 35C of the adhesive setter 35 andtransfers the bobbin 60C to the curing oven 35C. In other words, up tothis stage, the horizontal articulated robot 31 handles the bobbin 60C,as indicated by (31) at the bottom of the ordinate in FIG. 7.

[0089] Then, as soon as the bobbin 60A has undergone the adhesivesetting by the curing oven 35A, the horizontal articulated robot 31receives the bobbin 60A from the curing oven 35A and moves it to thegrinder 36. The grinder 36 takes 0.5 minutes for its processing.

[0090] After the bobbin 60A has undergone the grinding step, thehorizontal articulated robot 31 moves the bobbin 60A from the grinder 36to the polisher 37. The polisher 37 takes 8 minutes for its processing.The horizontal articulated robot 31 transfers the bobbin 60A to thepolisher 37. In other words, up to this stage, the horizontalarticulated robot 31 handles the bobbin 60A, as indicated by (31) at thebottom of the ordinate in FIG. 7.

[0091] After the bobbin 60A has been transferred to the polisher 37, thehorizontal articulated robot 31 loads the bobbin 60D from the loader 32and moves it to the inner coat stripper 33 for the stripping of theinner coat. After the bobbin 60D has undergone inner coat stripping, thehorizontal articulated robot 31 moves the bobbin 60D from the inner coatstripper 33 to the connector part inserter 34 so that the connector partis slipped on. After the bobbin 60D has undergone the slipping on of theconnector part, the horizontal articulated robot 31 moves the bobbin 60Dfrom the connector part inserter 34 to the curing oven 35A of theadhesive setter 35 and transfers the bobbin 60D to the curing oven 35A.In other words, up to this stage, the horizontal articulated robot 31handles the bobbin 60D, as indicated by (31) at the bottom of theordinate in FIG. 7.

[0092] After the bobbin 60D has been transferred to the curing oven 35A,the horizontal articulated robot 31 moves the bobbin 60A from thepolisher 37 to the unloader 38 for unloading. In other words, up to thisstage, the horizontal articulated robot 31 handles the bobbin 60A, asindicated by (31) at the bottom of the ordinate in FIG. 7.

[0093] After the bobbin 60A has been unloaded, the horizontalarticulated robot 31 receives the bobbin 60B from the curing oven 35Band moves it to the grinder 36. (At this stage the bobbin 60B hasundergone the adhesive curing in the curing oven 35B.) After the bobbin60B undergone the grinding step, the horizontal articulated robot 31moves the bobbin 60B from the grinder 36 to the polisher 37 andtransfers the bobbin 60B to the polisher 37. In other words, up to thisstage, the horizontal articulated robot 31 handles the bobbin 60B, asindicated by (31) at the bottom of the ordinate in FIG. 7.

[0094] After the bobbin 60B has been transferred to the polisher 37, thehorizontal articulated robot 31 loads the bobbin 60E from the loader 32and moves it to the inner coat stripper 33 for the stripping of theinner coat. After the bobbin 60E has undergone inner coat stripping, thehorizontal articulated robot 31 moves the bobbin 60E from the inner coatstripper 33 to the connector part inserter 34 so that the connector partis slipped on. After the bobbin 60E has undergone the slipping on of theconnector part, the horizontal articulated robot 31 moves the bobbin 60Efrom the connector part inserter 34 to the curing oven 35B of theadhesive setter 35 and transfers the bobbin 60E to the curing oven 35B.In other words, up to this stage, the horizontal articulated robot 31handles the bobbin 60E, as indicated by (31) at the bottom of theordinate in FIG. 7.

[0095] After the bobbin 60E has been transferred to the curing oven 35B,the horizontal articulated robot 31 moves the bobbin 60B from thepolisher 37 to the unloader 38 for unloading. In other words, up to thisstage, the horizontal articulated robot 31 handles the bobbin 60B, asindicated by (31) at the bottom of the ordinate in FIG. 7.

[0096] The above-mentioned steps are repeated sequentially to performthe terminal processing of the bobbin. The time (Tt) from the unloadingof the bobbin 60A to the unloading of the next bobbin 60B is referred toas the tact time. Similarly, the time (Tt) from the unloading of thebobbin 60B to the unloading of the next bobbin 60C is also tact time.The tact time (Tt) in this illustrative embodiment of the invention is10 minutes. The time required for each step is as follows: inner coatstripping=2 minutes, connector part insertion=4 minutes, adhesivecuring=20 minutes, grinding=0.5 minutes, and polishing=8 minutes. Thetotal time is 34.5 minutes using conventional processing.

[0097] However, in accordance with the invention, it is possible toreduce the tact time in the following ways. (1) For the steps (such asadhesive curing and polishing) which take a long time, the robottransfers the bobbin (as the work) to the adhesive setter 35 and thepolisher 37 so as to free itself. (2) The step (such as adhesive curing)which takes a long time is carried out in parallel processing fashionwith a plurality of identical units (the curing ovens 35A, 35B, and 35Cof the adhesive setter).

[0098] Referring to FIG. 7, the time Tx represents the delay betweencuring completion times between two successive curing ovens, 35A-35C.Since the curing time in each oven is the same, Tx can alternativelyrepresent the delay between starting times of successive ovens. Bystaggering the start time of each oven, parallel curing operations canbe achieved. The time Tx should be smaller than the desired tact timeTt, in this case 10 minutes. The time Tx can be adjusted by the numberof such ovens in use. For the illustrative embodiment shown, it wasdetermined that three such ovens would satisfy the tact timerequirement.

[0099] Moreover, for a further reduction of the tact time, thecontroller 31CONT of the robot 31 has priority for each step, andperforms processing according to this priority if there are a pluralityof bobbins (as the works) that can be processed simultaneously. Thepriority (in the descending order) is as follows: (1) unloading thebobbin which has undergone polishing by the polisher 37; (2) moving thebobbin to the polisher 37; and (3) loading a new bobbin.

[0100] Execution according to this priority is illustrated in FIG. 7.For example, in the neighborhood of 35 minutes on the abscissa (at whichthe bobbin 60D has been transferred to the curing oven 35A), thepolishing of the bobbin 60A is completed, and hence the unloading of thebobbin 60A is carried out in preference to the moving of the bobbin 60Bto the grinder or the loading of the bobbin 60E according to the rule ofpriority (1) “the bobbin which has undergone polishing by the polisher37 is unloaded”. Alternatively, for example, in the neighborhood of 36minutes on the abscissa (at which the bobbin 60A has been unloaded), thetransfer of the bobbin 60B (which has undergone heating) to the grinder36 and further to the polisher 37 is carried out in preference to theloading of the bobbin 60B to the grinder or the loading of the bobbin60E according to the rule of priority (2) “the bobbin is moved to thepolisher 37”. Furthermore, for example, in the neighborhood of 38minutes on the abscissa (at which the bobbin 60B has been moved to thepolisher 37), the bobbin 60E is loaded according to the rule of priority(3) “a new bobbin is loaded”.

[0101] As mentioned above, the present invention makes it possible tocarry out in a short tact time the assembling of cable terminal whichneeds a plurality of jigs and tools.

[0102] Another aspect of the invention is the pipeline fashionprocessing which can be seen in FIG. 7. In the neighborhood of zero toten minutes, bobbin 60A is moved from the coat stripper 33 to connectorpart inserter 34. At the end of processing in the connector partinserter 34, bobbin 60B is transferred to the coat stripper while bobbin60A is transferred to a first oven 35A. During curing, bobbin 60Bcompletes processing by the coat stripper 33 and the connector partinserter 34, and is then transferred to a second oven 35B. A similaroverlap can be seen in the neighborhood of 28-38 minutes, for example,where bobbin 60A is being polished and bobbin 60D begins its journey.This pipeline processing aspect of the invention allows for shorteningof the tact time.

[0103] The end chuck of the mechanical hand can change the direction ofthe member (optical cable) which it grips. This simplifies the mechanismof the processing apparatus and hence reduces the period and expenserequired for the development of the apparatus.

[0104] Within the working area of the robot, it is possible to handlevarious kinds of cables by replacing the mechanical hand and adding theunits.

[0105] According to the present invention, it is possible to carry outin a short tact time the assembling of cable terminal which needs aplurality of jigs and tools.

What is claimed is:
 1. A cable assembly method comprising: obtaining afirst bobbin of cable as a first work; sequentially delivering saidfirst work to each workstation in a first area having one or moreworkstations; delivering said first work to a first workstation in asecond area having a plurality of workstations, processing times of eachworkstation in said second area being about equal to each other, saidprocessing time being greater than a total processing time of said oneor more workstations in said first work area; and during processing ofsaid first work in said first workstation: obtaining a second bobbin ofcable as a second work; sequentially delivering said second work to saidone or more workstations in said first area; and delivering said secondwork to a second workstation in said second area, wherein completion ofsaid first work in said first workstation is followed by completion ofsaid second work in said second workstation by a period of time lessthan said processing time of said workstations in said second area. 2.The method of claim 1 wherein said obtaining steps include manipulatinga robotic arm to receive a bobbin of cable disposed in a loader, andsaid delivering steps include manipulating said robotic arm to transfersaid first and second works among said one or more workstations in saidfirst and second areas.
 3. The method of claim I further includingsequentially delivering said first work to each workstation in a thirdarea having one or more workstations upon completion of processing insaid first workstation and then delivering said first work to anunloader, said processing time of said workstations in said second areabeing greater than a total processing time of said one or moreworkstations in said third area.
 4. The method of claim 1 wherein saidworkstations in said second work area each provides an identicalfunction.
 5. The method of claim 3 further including, subsequent to saiddelivering said first work to an unloader, delivering said second workto said one or more workstations in said third area and then deliveringsaid second work to said unloader, wherein said first and second worksare delivered to said unloader in a time less than said processing timeof said workstations in said second area.
 6. The method of claim 3wherein said one or more workstations in said first area include anoutercoat stripper and a connector part inserter, said workstations insaid second area are curing ovens, and said one or more workstations insaid third area include a grinder and a polisher.
 7. The method of claim6 further including delivering a work from said polisher to saidunloader prior to delivering a work from said grinder to said polisher,when a work is available at each of said grinder and said polisher, anddelivering a work from said grinder to said polisher prior to loading awork to said one or more workstations in said first area, when a work isavailable at said polisher.
 8. A system for assembling cablescomprising: a first work area; a robotic arm disposed within said firstwork area; a first plurality of workstations disposed about said firstwork area and within reach of said robotic arm; a loading station forreceiving a bobbin of cable as a first work, said loading stationdisposed within reach of said robotic arm; a first workstation disposeddownstream of said first plurality of workstations; a second pluralityof workstations disposed downstream of said first workstation; and acontroller operatively coupled to said robotic arm, said controllerconfigured to cause said robotic arm: to retrieve said first work fromsaid loader and to sequentially deliver said first work to said firstplurality of workstations, wherein said first work is processed insequential fashion; to deliver said first work to said firstworkstation, said first workstation having a processing time greaterthan processing times of said first plurality of workstations; tosequentially deliver said first work to said second plurality ofworkstations; and to retrieve a second work from said loader andsequentially deliver said second work to said first plurality ofworkstations during processing of said first work in said firstworkstation.
 9. The system of claim 8 wherein said first workstation isa first oven.
 10. The system of claim 9 further including a second oven,wherein said controller is further configured to deliver said secondwork to said second oven while said first work is still being processedby said first oven.
 11. The system of claim 10 wherein said controlleris further configured to deliver said first work from said first oven tosaid second plurality of workstations while said second work is still insaid second oven.
 12. The system of claim 8 wherein said first pluralityof workstations includes an outer coat stripper and a connector partinserter and said second plurality of workstations includes a grinderand a polisher.
 13. The system of claim 8 wherein said robotic armincludes an articulated chuck configured to grip an end portion of saidcable and to provide approximately 180° of arcuate range of motion ofsaid end portion in a vertical plane.
 14. The system of claim 8 furtherincluding a second work area having a second robotic arm disposedtherein, a second plurality of workstations disposed in said second workarea about said second robotic arm and within reach of said secondrobotic arm, and a second loading station for receiving said bobbin ofcable, wherein said bobbin of cable is processed in said second workarea prior to being processed in said first work area.
 15. A system forassembling cables comprising: means for receiving a bobbin of a cable asa first work; a first means for performing a first plurality ofoperations on a cable portion of said first work; a thermal processingmeans for a thermal treatment of said cable portion, said thermal meanshaving at least a first and a second heating unit; a second means forperforming a second plurality of operations on said cable portion; androbotic means for delivering said first work to said first means, thento said first heating unit, and then to said second means, said roboticmeans configured to deliver a second work to said first means and thento said second heating unit, while said first work is being processed bysaid first heating unit.
 16. The system of claim 15 wherein said roboticmeans includes a chuck having an approximately 180° arcuate range ofmotion in a vertical plane, for positioning a cable end portion of saidwork which is received in said chuck.
 17. The system of claim 15 whereinsaid robotic means is further configured to deliver said first work tosaid second means while said second work is being processed by saidsecond heating unit.
 18. The system of claim 15 wherein said first meansincludes an outer coat stripper and a connector part inserter and saidsecond means includes a grinder, a polisher, and an unloader.
 19. Thesystem of claim 18 wherein said robotic means is further configured todeliver a work from said polisher to said unloader prior to delivering awork from said grinder to said polisher when a work is available at eachof said polisher and said grinder, and further configured to deliver awork from said grinder to said polisher prior to loading a work to saidfirst means when a work is available at said polisher.
 20. The system ofclaim 15 further including a third means for performing a thirdplurality of operations on said cable portion, wherein said first workis processed by said third means and then delivered to said first means.